Four paying subscribers of ChatGPT, Claude, Grok, and Gemini have filed a class-action lawsuit in the U.S. District Court for the Northern District of California on September 18. The plaintiffs accuse Anthropic, OpenAI, SpaceXAI, and Alphabet of forming an illegal agreement to deliberately slow down the pace of artificial intelligence development, which they claim violates Section 1 of the Sherman Antitrust Act and reduces the value consumers receive from their paid AI subscriptions.

The case, titled "Buist v. Anthropic PBC" with docket number 3:26-cv-10693, represents a proposed nationwide class, with attorney Nick Rowley leading the legal team. The complaint alleges that these four companies, through public statements and coordinated actions, agreed to decelerate AI progress, thereby undermining the competitiveness and worth of their subscription-based services.

The central evidence cited is an article published by Anthropic's CEO, Dario Amodei, on September 12, 2026. In that piece, Amodei called for an industry-wide, synchronized slowdown in AI advancement. Shortly thereafter, OpenAI's CEO Sam Altman, SpaceXAI's CEO Elon Musk, and Alphabet's DeepMind leader Demis Hassabis each publicly endorsed this approach. The lawsuit also points to earlier signs of coordination, noting that in July 2026, multiple AI lab executives signed a joint statement signaling their collective stance.

According to the plaintiffs, these declarations go beyond simple safety advocacy and instead constitute an anti-competitive pact. As a result, consumers are left without access to the faster, higher-quality AI services they should have received. The lawsuit seeks a court ruling that the four companies have breached antitrust laws and requests appropriate damages. As of the time of this report, Anthropic, OpenAI, SpaceXAI, and Alphabet have not issued any public comment regarding the litigation.